Silverfish

Scientific Name: Lepisma saccharina

How to identify a Silverfish

Silverfish are wingless insects. Their tapered body and fast wriggling movement, along with their silvery scales gives them some “fish-like” features.

Where are Silverfish commonly found?

Silverfish live in moist areas, with a high humidity. In buildings they are commonly found in roof voids, sub-floors, bathrooms and laundries. They are commonly found in stored cardboard boxes.

Silverfish are nocturnal, running away from light and vibrations – so they like dark, undisturbed areas.

Silverfish have a strong preference for materials containing complex sugars such as starch. Complex sugars are found in many materials including paper, glue, carpet and clothing. Silverfish will also eat other plant and animal materials such as cotton and leather.

Why are Silverfish considered a pest?

Silverfish can cause significant damage to clothing as well as spoil food. However, it is their habit of eating books, photos and documents that makes them a pest.

What is the biology and lifecycle of Silverfish?

Silverfish eggs are whitish and oval-shaped, about 0.8 mm long. They will often be found in groups of up to 60 eggs in cracks and crevices. 

Young silverfish look very similar to the adult, except they are smaller and whiter in colour.

Adult silverfish can be up to 3 cm long. If you find a large silverfish, the chances are they have been laying eggs for a long time and you could have a big problem.

Adult silverfish can live for 2-8 years, getting progressively bigger. In that time they can lay a lot of eggs… so a large silverfish may mean you have a big problem

Management Tips for Silverfish

Silverfish Control:

• Throw out any cardboard boxes used for storage and replace with sealed plastic containers.

• Carry out a thorough vacuum of rooms (especially the room edges and under furniture) and cupboards.

• Remove any clothes and belongings from areas to be treated and check for silverfish.

• If the clothes and belongings are not susceptible to heat, place in a black plastic bag and leave in the sun for 1-2 hours, to kill any silverfish and eggs on the clothes.

Silverfish Prevention:

• Silverfish like moist / high humidity environments, reducing humidity in susceptible areas is the key; use de-humidifiers, air-conditioning and fans and in bathrooms, kitchens, laundries, roof voids, sub-floors and any other damp areas.

• Try and find out if there is a reason for the moisture / high humidity and fix it. (Poor drainage under the house, leaking roof, leaking taps, tumble dryer not vented to the outside are common problems).

• It is impossible to remove all food sources (clothes, paper and books), but you can make it hard for them to access. Keep these items off the floor and stored in sealed containers if possible.

• Maintain a strict hygiene regime. Not only vacuuming thoroughly, including in all those dark corners, but cleaning up any spilt food and storing open food in sealed containers. Make sure the contents of the vacuum bag are placed in a sealed bag and put in the bin after each use.

• Use caulking agents to fill any gaps in walls and skirting boards.

• Carefully check any cardboard boxes you may bring into the house to avoid re-infestation.